Disturbances in the urinary and rectal functions are a great problem both for the individual person involved as well as for nursing attendants, etc. Urinary incontinence is quite common, and from a nursing point of view is very time-consuming, requiring the changing of clothing, bedding, etc.
There have been attempts to solve these problems in a number of different ways. For example, technical means for the collection of urine have been employed. These work tolerably well in the case of men, but are much more difficult to realize with women.
There have also been attempts to electrically stimulate the pelvis floor through the implantation of electrodes in the pelvis floor musculature. These electrodes are then connected to a pulse generator which is placed subcutaneously, and which can in turn be supplied e.g. electromagnetically, with pulses from a transmitter placed outside the body. This method, however, requires surgical intervention, and is relatively complicated and costly. Examples of such implantable devices are disclosed in U.S. Pat. Nos. 3,543,761; 3,667,477 and 3,870,051.
In another method contraction of the urethra is achieved by means of electrical stimulation by means of electrodes arranged on an element carried intravaginally or anally. Generally, however, elements of this type are made of a rigid plastic material of circular cross-section, and the electrodes frequently constitute peripheral metal rings. Examples of such devices are set forth in British Pat. No. 1,286,075 and in U.S. Pat. No. 3,943,938. Apart from the discomfort associated with the wearing of such a hard element inside the body, there is also a risk of it sliding out. Moreover, a stimulation of the whole pelvis region is obtained through the peripheral electrodes, and this is not always appropriate.
In U.S. Pat. No. 4,106,511, an improved design of a stimulator is described. This electrical stimulator, which is intended for vaginal or anal placement, comprises an element consisting of a flexible material which is expandable so as to achieve secure attachment in the body. The element disclosed in this patent is provided with a substantially planar end wall at its inner end in its applied position. This end wall is intended to facilitate placing and retention of the element in the desired position. In spite of the fact that the element in this patent has a shape which is not quite rotational-symmetrical, there is a great risk of its turning, and as a result two groups of electrodes may point in an incorrect direction, and thus obtain an undesirable direction of stimulation. This tendency of spinning away from the desired position is initially due to the fact that the electrodes are placed opposite one or more protuberances which are intended to facilitate the maintainance of the element in a selected vaginal or anal position. However, a normal vagina has a cross-sectional shape which includes a dimension at right angles to the longest dimensions of the cross-sections of the known element which is longer than those dimensions, and therefore there is a resulting tendency for the device to spin or turn.
It is therefore an object of the present invention to provide an electrical stimulator for vaginal placement which in particular has an improved design compared with those of the prior art, such as that of U.S. Pat. No. 4,106,511, which in spite of its disadvantages is probably the best of its kind produced up to now.